Automatic Dependent Surveillance-Broadcast (ADS-B) is part of a standard that defines a cooperative next generation air traffic system which will increase the situational awareness from aircraft to aircraft and aircraft to air traffic control. ADS-B establishes requirements for an aircraft to transmit data regarding its navigation. ADS-B avionics devices may be installed in aircraft that also include older generation air traffic system devices such as an onboard transponder which responds to ground-based secondary surveillance radar interrogations.